With the development of the laser processing technology, particularly the development of the optical system, a conventional f-θ (scanning objective) optical lens can achieve a telecentric effect by a combinational design of several optical lens, i.e. the telecentric optical lens. However, due to a configuration of the optical parameters of the several optical lenses and a design of distances among the several optical lenses of the telecentric optical lens, the telecentric optical lens cannot meet achromatic and relatively large aperture requirements at the same time.